Bug#461489: A clarification; X settings for numlock-on not useful on keyboards that lack a numlock key.
A clarification: This laptop has no numlock key as such - not even
in its overlay keyset. The only way to toggle the numlock is to plug
in an external (USB) keyboard and press the key on that - or to have
the numlock setting inherited from my standard X settings, which is
what was happening here.
Thus, every time I booted up, my X settings were setting the numlock
state (and by implication the fn-key state), and there's no way on the
keyboard to unset it.
The "fix" then is to change my X settings so as to NOT have numlock-
by-default (which is my preference on fullsize keyboards).